Booster switch system



March 8, 1938.

M. F. PETERS BOOSTER SWITCH SYSTEM Filed Jan. 7,v 193s INVENTOR ATTORNV BYMELv/LLE F. PETER:

Patented Mar. 8, 1.938

UNITED STATES PATENT OFFICE noosTEn. SWITCH SYSTEM Melville F. Peters, Riverdale, Md. Application January 1, 1936, serial No. 57,919

s cm (ci zoo-1 6) (annua under than: or Much s, 188s, as .mended April so. 192s; a'zo o. G. '151) be adversely aiected by electrical oscillations set up in the ignition system where these oscillations are permitted to be impressed upon the battery supplying the radio receiving or other apparatus.

To facilitate the starting. oi.' an internal cornbustion motor carried by a movable craft, a booster coil fed from a storage battery has been employed with good results in so far a's starting the motor was concerned. However, after a motor has been started and the high tension ignition voltages are supplied by a magneto the booster coil is no longer needed. When the primary circuit of the coil is opened by means of a conventional switch, high frequency oscillations set up in the ignition circuit by the magneto will worl;J back from the booster coil, by way of the capacity across the open switch, to the battery and thus cause interference in a radio receiving set connected to said battery. 4

'I'he principal object of this invention is to provide a system ,wherein electrical oscillations generated in an internal combustion motor ignition system or the like areJprevented from passing into a, storage battery by way of the coupling due to the capacity across an open switch connected to a booster coil or the like'. i

Another objectof this invention is to provide a switch'mechanism wherein the switch contacts, when open, are electrostatically and electromagneticallyshielded from one another by a member maintained at a fixed potential.

Otherl and further objects will be apparent to one skilledin the art to which this invention appertains by reference to .the following specification and the accompanying drawing, wherein the single figure shows partially in section and par- .tially diagrammatically one embodiment of the invention. ,l

In the drawing, I is a'lmetallic casing and 2 is a conductive rod having a truste-conical switch contact afilxed to one end thereof. The rod 2 is Amounted for axial movement in insulating bushings 5 and 1. The bushing 5 is mounted in an. opening in the end wall 4 of the casing, while the bushing 1 is mounted in the sleeve 3 carried by booster coil to spark plug leads 438 leading to o the shielding partition i which divides the casing I into two compartments. The movable switch contact 9 is aillxed to the rod 2 bymeansl of a set screw I0. vA helical spring II is interposed between the shielding bushing `1 and the movable switch contact 9. 'I'he spring II is prevented from contacting with the rod 2 by means of an insulating sleeve I2. The spring is also prevented from bearing directly upon the switch contact 9 by means of the annular insulating member I3 surrounding the rod 2. Opposed to the movable switch' contact 9 and in line therewith is a fixed contact I4 mounted on the screw support member I5 which in turn is mounted in insulating member i6 carried jointly by the casing I and 15 `the partition 6. Nut I1 on screw I5 holds the conductor IB in rm contact therewith. Opposed to the movable contact 3 carried by connecting rod 2 and in line therewith isI a second fixed contact I9 which is carried byl bracket 20 mounted on the casing I by screws 2l The contact I9 is fastened to the bracket 20 by means of screws 22 and 23 but is insulated from the bracket 20 by means of the insulating bushings and washers 24, 25 and 26, respectively. The con- 25 ductor 21 is effectively connected to the switch contact I9 by means of the screw 23 and its as-4 sociated holding nut. The switch casing I may be grounded at 28 by meansot the conductong which is grounded at 30, or the case itself may 30 be grounded. The conductor 21 connected with switch contact IS is connected to one terminal of a battery 3l, the other terminal of which is grounded at 30. The' battery 3| is shownconnected to\r.dio `or other precision apparatus at 32. The conductor IB connected to switch contact I4 is connected by way of the breaker points 33 to one terminal of the primary 35 of the boostf ler coil, the other terminal of the primary of which is connected to ground at 30. T he breaker 40 cam 34 is associated with the breaker points 33 in such a manner as to periodically break the primary circuit of the booster coil when the cam is rotated. The secondary :ity of the booster coil has one terminal thereof grounded, while the 4- other terminal is connected to a distributor arm 31 which rotates synchronously with breaker cam 34. The distributor arm 31 upon being rotated alternately connects the secondary 36 of the spark plugs 39. A conductor 4|) is connected to the distributor arm 31 and also to a switch 42 adapted to connect conductor 40 to conductor 43 leading to a magneto or other source of spark plug potential 4I. The switch 42 is mechanically 56 connected to link 44 which in turn is connected/to lever 45 which is pivoted on a fixed/ pivot 48. The rod 2 has mounted thereon an operating handle 41 which is pivotelly-eenneeted te lever 4s by means of a pin 48. y

The operation of the device is as follows: When it is desired to start the motor, the rod 2 is slid axially downwardto bring movable switch contact 9 against fixed contact I4 and to bring contact 3 against xed contact I9. This effectively completes a circuit through the primary 35 of the booster coil by way of the following circuit: ground 38, battery 3|, conductor 21, screw 23, fixed contact I9, movable contact 3, conducting rod 2, contacts 9 and I4, screw I5, con= ductorl I8, breaker points 33, to primary 35, and` thence to ground 30. Upon the rotation of the motor in being cranked, the breaker cam 34 periodically breaks this circuit at breaker points 33 and causes high voltages to be set up in secondary 36. 'I'he high voltages in the secondary 36 cause a spark at the electrodes of spark plug 39 by way of the distributor arm 3l, conductor 38. and ground. During this phase of the starting the switch 42 is opened and the magneto 4I is not eiiectively connected with the distributor or spark plugs.

When the motor has started and it is no longer necessary or desirable to supply ignition potentials by means of the booster coils, the. spring l I is permitted to drive the conducting rod 2 upwardly and open the circuit to the primary of the booster coil at two points; namely, between contacts 3 and I9 and contacts 3 and I4, As the booster coil switch opens, the magnetoswitch 42 is closed by the rocking of the lever 45 about its pivot 46.

`Sparking potentials are thereafter supplied from the magneto by way of conductor 43, switch 42, conductor 40, .distributor arm 31, lead 38, to spark plug 39,D and thencedto ground. Heretofore in the art, when the motorhas been started and the booster coil circuit is open, it is found that certain oscillations generated in the magnetospark plug circuit have worked themselves back to the battery ucircuit by way of the electrostatic capacity existing .across the terminals of the booster coil circuit switch. It is to prevent this undesired operation that applicants switch dis- `closed herein was developed. When the rod 2 is moved by spring Ii to its uppermost position, such as is shown in the drawing, the booster coil circuit is not only opened but' the contacts I4 and I3' are effectively shielded from one another by the conductive partition 6, the conductive con-A tact 3, and sleeve 8. With this type of structure, it is possible to so completely isolate the ignition system from the battery 3i as to render the battery 3i available for the energizatign of radio receiving apparatus, such as that shown at 32, or other precision apparatus.

In the drawing and specification above, applicant has disclosed a booster coil systemem'- ploying a single distributor i'or distributing sparking potentials to each of a plurality of spark plugs 1 in turn from a single booster coil or magneto, but is to be' understood that other .and equivalent systems may be devised.` Applicants switch is ,intended for use whenever and wherever it is desirable to electrostatically shield open switch conernment of the United states of America 'for' governmental. purposes without the paymentv of any royalties thereon -or therefor.

herein:

airain I claim:

1. A switch mechanism comprising a metallic casing having two separate compartments, a fixed contact insulatingly mounted in each lcompartment, a pair of electrically and mechanically interconnected movable contacts simultaneously movable to engage each contact or said pair with a respective one-of said fixed contacts when the switch is in the closed position, one of said movable contacts being in each compartment, and means including one 'of said movable contacts for electromagnetically shielding said ilxed contacts from each other when the switch is in the open position, said ,one movable contact completing the closure between said compartments when in open position.

2. A switch mechanism comprising a metallic casing, a metallic shield provided with an opening therein interposed in said casing and dividing said casing into two compartments, a' pair of fixed contacts insulatingly mounted within said casing, one in each of said compartments, a conducting member extending through the opening in said metallic shield and insulated therefrom, a pair of movable switch contacts mounted on said conducting member, one in each of said`compartments, for engaging with respective ones of said fixed contacts when the switch is in closed position, means for moving said conducting member to open said contacts, and means comprising one of "said movable contacts for closing the opening in said shield and grounding said movable contacts when said switch is in an open position.

3. A switch mechanism comprising a metallic casing, a pair of fixed contacts mounted in said casing and insulated therefrom, a pair oi interconnected movable contacts for completing a circuit between said iixed contacts when said movable contacts are moved into juxtaposition with said fixed contacts, continuously acting means tending to move said movable contacts to the open position, and means comprising at least one of said movable contacts for electrostatically shielding said xed contacts from each other when the movable contacts are moved away from the fixed contacts. v

4. A switch mechanism comprising a metallic casing, a metallic shield provided with an opening therein interposed in said casing and dividing said casing into two compartments, a pair of .fixed contacts insulatingly mounted within said "position, means for moving said conducting member to open said contacts, and means comprising a frusta-conical plug member carried by said conducting member for closing the opening in saidv shield and electrostatically shielding the fixed contact in one compartment from the xed contact in the other compartment.

5. A switch mechanism comprising a metallic casing, a. metallic partition dividing the casing into two compartments, said partition being provided with an opening therethrough, an insulating bushing having an annular section interposed in the. opening in said partition, a, pair of fixed contactsm'ounted within said casing, one

in each compartment insulated therefrom, a conducting member mounted in said insulatingibush- A ing andextending intocboth ofsaid compartpartments, for engaging with respective ones of said xed. contacts when the switch is in closed position, and means for moving said conducting.

member and the contacts mounted thereon for opening said switch and moving`one of said movable contacts to cover .said opening.

6. A switch mechanism comprising a-metallic casin8. `a metallic partition dividing'the casina into two compartments, said partition being provided with an opening therethrough, an insulatingzbushing having an annular section interposed in the openinslin said partition,;a pairof fixed contacts mounted within saidcasins, one

--said iixed contacts in each compartment insulated therefrom, a conductins member mounted in said insulating' bushing and extending into both ot said compartments. movable switch contacts mounted on said.

conducting member, one in each of said compartments, vfor ensasin's with respective ones ct whenthe switch is in closed position, and means for moving said conducting member and the contacts mounted thereon for opening said switch and moving one of said movable contacts to cover said opening, and means acting on said conducting member normally tendina to move said member to the open posinon.

Mmmm F. PETERS. 

